US2468132A - Piano action - Google Patents

Description

c. F. STEIN PIANO ACTION April 26, 1949.

2 Sheets-Sheet 1 Filed April 9, 1945 2 I v INVENTOR.

CHARLES FREDERICK STEIN C. F. STEIN PIANO ACTION April 26, 1949.

2 Sheets-Sheet 2 Filed April 9, 1945 FIG. 3

INVENTOR CHARLES FREDERICK STEIN FIG. 4

WMW

4770B /1/ VJ Patented Apr. 26, 1949 PIANO ACTION Charles Frederick Stein, Ivoryton, Conn., assignor to Pratt, Read and Company,

Inc., Ivoryton,

Conn., a corporation of Connecticut Application April 9, 1945, Serial No. 587,272

16 Claims.

This invention relates to piano actions and, while it is of general application, it is particularly suitable for embodiment in pianos of the low-upright type.

The increasing popularity of the low-upright and spinet models of pianos in recent years has raised the problem of devising a satisfactory piano action. In the old style high-upright pianos, it was customary to interconnect the capstan on the end of each key to its associated hammer butt through a strut linkage including a flyjack for releasing the hammer at the end of the stroke. This piano action was of such construction that it had to be mounted entirely above the level of the keys, so that a corresponding vertical height in the piano frame and case was required, In the low-upright style of piano there is insuflicient vertical space relative to the level of the keys to accommodate this type of action.

Certain piano actions have been devised for the new low-upright pianos having a so-called drop-action, that is, a mechanism comprising a number of links droppin below and behind the piano keybed. Such mechanisms have in some instances introduced undesirable frictional dissipation of the striking force initiated by the key and a certain sluggishness in the return of the striking hammer to its rest position, resulting in a slow piano action, and in general have been clumsy to handle. Also in any piano actions there are a number of elements which must be made adjustable, both for proper setting of the striking hammer in the first instance and to compensate for subsequent wear, shrinkage of wooden parts, etc. In the drop-type action, these adjustable elements are generally below and behind the piano keybed and quite inaccessible for adjustment without at least a partial disassembly of the piano.

It is an object of the invention, therefore, to provide a new and improved piano action which is of general application but which is particularly suitable for embodiment in low-upright pianos, and one which will obviate one or more of the shortcomings and limitations of the prior art piano actions of this type.

It is another object of the invention to provide a new and improved piano action which is extremely simple and rugged in construction, and reliable and fast in operation.

It is still another object of the invention to provide a new and improved piano action which is particularly suitable for installation in a lowupright type of piano, and in which all of the adjustable elements are accessible for ready adjustment from above and in front of the keys.

( stantially erated by ment of the third arm.

For a better understanding of the invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings While its scope will be pointed out in the appended 1 claims.

' rail cloth 13.

extending above its associated key II and disposed to be operated by a capstan l5 mounted at the outer end of the key ll.

c from a flange '23 vscribed is .a damper is pivoted at Ma to a flange [5 depending from and secured to a rail IS. The three-part frame also includes a second arm or actuator ll pivoted to the arm l4 near its free end at the point Na and depending from the arm 14. The actuator I! has a contact surface l'lb engaging the hammer H] for actuating the same, specifically engaging the end surface on the hammer butt ma. One of the arms '14 and I1, specifically the arm M, has an abutment Mb thereon near its free end and beyond the pivot point Ila, and the frame includes also a third arm or fiy-jack i8 pivoted or hinged at I8a to an extension lie of the arm I! beyond its pivot point '-l*|a"an'd normally engaging the abutment also includes biasing means such as a helical compression spring IQ for normally maintaining the arm 18 in engagement with the abutment I52) and retaining the collapsible actuating mechanism in the form of a'rigid frame.

The piano action of "the invention also includes adjustable means for collapsing the actuating mechanism at a predetermined adjustable point in the travel'of'the hammer It to permit the hammer to "fall "backfrom a string-striking position prior to the release'of its associated key 1 i. Such ccllapsingmeans comprises means for breaking one of the hingesofthe hinged actuating frame, .specifically,a stop 20 adjustably supportedin a'rail'2l of an extension of'the arm l8 beyond its pivot point We during the movement of the actuating mechanism intoistriking' position. This engagement is s'hoWnin Fig.2 which will be referred to in more detail in connection with the operationof the piano action. Engagement of the arm IS with the stop '29 is effective to disengage the arm from the abutment Mb to collapse the frame.

The piano action of the invention also includes adjustable means for limiting the extent of the collapse of the actuating frame .or mechanism to support the hammer near string-striking position so long as the key is depressed. This means is in the form of ana'djustable stop '22 on one of the arms ofthe frame, for example the horizontal arm 14, engaging-a butt 11f on the arm ll upon collapse of the frame,itherebyito limit the extent of collapse thereof. The stops 20 and 22 are provided with threaded adjusting eyes or .heads "20a, 22a, respectively,

and theseare both accessible for adjustment "from above the piano key 5 l and atthe front of thepianoaction as a whole.

The hammer butt l'iJa' is pivotally supported at secured to 'a lower action rail 2 The hammer '10 ,is biased into its position of rest by means of a spring 26 mounted on a spring rail 21. Associated with the action de- 28 supported by a damper wire 29 from a damper lever 30 pivotally mounted at 30a from a flange 3| secured to the lower action rail 24. The armfl is provided with an extending rod l'ld engaging the felt'36b secured to the lower end of'the damper lever 36. The lower portion of thedam per lever 3i! is also provided with a damper felt 30c adapted to be engaged by a damper-lifting rod 32. A hammer rest rail '33 is provided for supporting the hammer It in its position of rest.

It is believed that the operation of the piano action of the invention will be apparent from the foregoing description. In brief, however, assumingthat the-mechanism-is in the positionof rest as shown. in Fig. 1,.4depression oftthekey .l I

Mb. The actuating frame ancl'in 'thepath of movement 5 its string-striking position,

ham-mer "butt ita maintaining its is efiective to rotate the collapsible actuating frame lt--Hl8 in a clockwise direction about its pivot Ma, the spring l9 retaining the arm It in engagement with the abutment Mb and thus retaining the mechanism in the form of a rigid three-hinged frame. The frame l4-I'l-i8 is thus actuated as a unit, its actuating face i'i'b contacting the butt Illa of the hammer ID and rotating it in a counterclockwise direction into string-striking position. Prior to reaching the "string-striking position of the hammer ill, the

head portion of the rod l'ld engages the operating arm 39b of the damper lever 30 to lift the damper from the-string in order to produce a sustained ncteso long aslthe key is depressed.

At about the time that the hammer it reaches the extension of the arm 18 beyond the pivot point lea engages the adjustable stop 20, which disengages the arm 18 from the abutment Mb and is effective to collapse the frame member "l-d-i-'l-i 3, permitting the arm H to rotate about its pivot Na in a counterclockwise *directionuntil the butt of the arm engages the adjustable stop 22. This permits thehammer lfl to fall back, rotating in a clockwisedi-rection aboutits pivot point the, the engagement with-the contact face l'l-b-of the arm-H. This final position, after the striking of a note, is maintained so long as the 'key 1! is depressed. This final position is' illustrated in Fig. 2 of'the drawings.

Upon release of the lrey-J I, the weight of the hammer I i and of the actuating mechanism l tl l-i 8 causes it tofallback rapidly. During this return to rest position, the extension :of the arm i8 is released from thestop 2!] andthe compression spring t9 snaps it backuuick1y into engagement with the arm I14 at the abutment Hlb'so that, upon a subsequent'striking of the key H,

it is in position immediately to repeat-the action described above. The force :of the spring 18 is so adjusted in relation to the weights and inertias' of the several parts of the piano action that the arm or fly-jack 1821's:restored to its rest .position :during'the return movement of :the action mechanism as a whole, preferablyxsome :distance .prior to reaching the rest position of the key and piano :actionmechanism. Thiszensures that therm'echanismis ready for a repeated .strokezof the .key zll in .the .very L-minimum of time and thus contributesrto zan extremely-fast piano action. Intact a'pianist'isable-to feelin his .fingerswhen-the :action ismspositionito .again move the hammer and with The .present mechanism, in view of the fact ithatthe parts are in position ,forstriking another blow wviththe :hammer "before the'key issin final rest position the repe- :tition :blow can -be:sta1'=ted;inless -:time than it requires theparts andkey to reacha final position of rest.

On the other .hand, as :mentioned above, the

,butt of the'arm l1 ismaintained inrengagement 6 of arm I! by the stop 22 maintains a rigid con- 34-41-38 upon disengagement of the arm 38 nection between the ke II and the hammer butt mm the abutment 310. The arm 38 is provided 1a to permit repetitive blows from such interwith an extension 38b which is engaged by the mediate position. This condition continues until adjustable stop 20 in its path of movement tothe action mechanism returns nearly to its posiward the string-striking position of the hammer tion of rest, as illustrated in Fig. 1, in which pol0.

sition the stop 22 is disengaged from the arm ll. The general principle of operation of the modi- In other words there is no lost motion between fled form of invention illustrated in Figs. 3 and 4 the key N and the hammer ID from the time that is entirely similar to that described above and the hammer is first struck until the action mechneed not be repeated. The position of the sevanism returns nearly to its position of final rest eral parts in string-striking position of the hamas represented in Fig. 1. It Will be understood mer I0 is shown in Fig. 4, the dotted-line posialso that the stop 22 acts in a conventional mantion of the hammer I 0 representing its striking ner to determine the position to which the hamposition and the solid-line position, the position mer l0 returns when the key is maintained deto which the hammer falls back while the key pressed. II is maintained depressed. The piano action of It is noted that the piano action described Figs. 3 and 4 has generally the advantageous overcomes the severa1 disadvantages and limitacharacteristics described above in connection tions of the prior art piano actions for loW-upwith that of Figs. 1 and 2. The choice as beright pianos described above. That is, the adtween the two forms of the invention is deterjustable capstan l5 and the adjustable eyes 20a mined primarily by the nature of the installation and 22a of the stops 20 and 22, respectively, are and the convenience in mechanically accommoall above the keybed and in front of the major dating the different arrangement of the parts of components of the piano action so that they are the collapsible actuating mechanism.

readily accessible from the front of the piano. 25 While there have been described what are at At the same time, the hammer I0 is only slightly present considered to be the preferred embodiabove the keybed, thus permitting the installation ments of the invention, it will be apparent to of the piano action in a very low-upright piano. those skilled in the art that various changes and Also the piano action as a Whole extends only a modifications may be made therein without defew inches, for example about two inches, below parting from the spirit or scope of the inventhe keybed so that al1 parts thereof are reasontion.

ably accessible for repair, replacement or ad- What is claimed as newis:

justment without disassembly of the piano as a 1. An action for a piano including a plurality whole. At the same time, the actuating mechof keys comprising, a pivoted striking hammer, anism is, during the striking operation, in the a single pivoted normally rigid collapsible actuform of a simpl ri i three-hinged frame l4- ating mechanism disposed to be operated by a l1l8 including only a single pivotal connection key d includi at Ma, thu a e y m n n the dissipation mer for actuating the same, said ham of the key-striking force by friction, which results free t m v ith respect t id pgrtj from the use Of the complicated action of the 40 mechanigm and means for collapsing s p i r rt inv lvi a l r e number f relatively anism at a predetermined point in the travel of pivoted elementsoweve the collapse of the said hammer to permit said hammer to fall back actua mechanism po reaohlng e S from string-striking position prior to release of striking position is effective to permit the imit associated k mediate rebound of the hammer I0 and an ex- 2 An action for a piano including a plurality t y rapid return of the elements Test of keys comprising, a pivoted striking hammer, a sition up n r l as of th pian key N for a v single pivoted ri id actuating frame disposed to rapid repetitious movement of the entire mechabe engaged by a key and engaging 53,1 1 hammer nism. for actuating the same, said hammer being free The modified form of action illustrated in Figs. to move jndep 3 and 4 is generally similar to that of Figs. 1 and actuating fram jncludin 2 and such elements as they correspond to those hinged togeth of Figs. 1 and 2 are identified by the same referin fixed positi ence numerals. The essential difference of the means for h piano action of Figs. 3 and 4 is that the disenframe t 11 gageable arm 38 of this modified form is pivoted point in th at 38a from the main portion of the horizontal permit said hammer t fall back fr arm 34 and engages an abutment 310 formed in striking 1 the main portion of the depending arm or actukey. ator 37 Which is pivoted at 37a near the free 66 3. An action for a piano including a p rality end of the horizontal arm 34, wh1ch 1s substanof keys comprising, a pivoted striking hammer,

tially the inverse of the arrangement of Figs. 1 e, s ngle pivo'be and 2. In this instance, the spring 39 is a tension ating mechanism including a b t spring rather than a compression spring and Zontal arm disposed to biases the arms 34 and 31 toward collapse w c a depending arm engaging said hammer for acis opposed by the arm 38. As in the arrangement m tin th Same, and me of Figs. 1 and 2, the arm 31 is provided with a mechanism ata predeterm' contact surface 31b for engaging the hammer o s id h m t perm butt Illa to actuate the same and with an exback from string-striking position prior to retension IOd 31d terminating in a, head 376 for o lease of its associated key,

actuating the damper lever 30. The arm 34 is 4. An action for a piano including a plurality provided with a projection 34 Which Coope of keys comprising, a pivoted striking hammer, ates with an adju ta le st p 2a upported in an a single pivoted normally rigid collapsible actuextension 31] of the arm 37 to limit the exating mechanism including a fly-jack as an ele tent of collapse of the actuating mechanism ment thereof and disposed to be operated by a a pivoted' striking hammer-- havin'gza contact butt, a single pivcted normally}; rigidr'col-lapsible "actuatingimechanism disposed: to be operated by a key-:and including a portion adapted r to contact: said hammer =butt for actu-s atingth'e same, said hammer being free 'tOimOVB with respect' to: said portion-:ofr said. mechanisms and means" for collapsing ssaidmechanism ataa predetermined point in the travehoisaidhammer: to=:permit-said hammer to iall back Hamstringstriking apositi'on prionto release ofwits associated:

6;.An action for -apiano? including: a plurality of keys comprising: a pivoted? striking ;,hammer;-: a single pivoted collapsible actuating: mechanism; disposed tobe operated byia akey and-engaging said hammer ion-actuating the same, -saida ham-1 1 merbeing-free-to moveiwithrespect to said mechanism; biasing means for normally retaining saidz mechanismin-the -form of: a rigid .actuatingframe: member; andtmeans for collapsing said mecha nism at a predetermined point in the travelsrofiz said hammer to permit isaidrhammerwtozfall' back from string-striking. position'priorsto. release. of its associated' key.

7 An actionvior a piano :includin'g'a/ plurality of keys comprising, a pivoted strikinghammen-a single pivotedrigid hinged actuating irame in. cluding a substantially. horizontal. arm disposed. to be engaged bya-keyand a dependingarm engaging said hammer for actuatingthe same-and; means -for breaking a hinge of 'said actuating member to collapse-.theisame at'a predetermined. point in the travelof saidhammer to. .p ermit said" hammer to fall back from string-strikingposition prior to releaseofits'associated keyn- 8. An action icra piano including.ia-plurality-i of keys comprising, a pivoted striking hammer; asingle normally rigid collapsible actuating-mean anism-lincluding a substantially. horizontal first. armv extendingaabove its associatedkey-tube: operated thereby and pivoted-at one "end and: a: second armdepending from said =firstarmvnea'r its free end and engagingsaidhammerior :actu-.satingf same, .and. means "for: collapsingqsaid mechanism-eta predetermined pointinthe travel: of. said hammer to --permit saidhammer: tozialls. back from:string-striking pos-ition priorfto release: of.-its associated key.-

9. An action for a piano including a plurality: ofkeysycompiising; a pivoted-striking hammer"; a single pivoted rigid.- three-part hinged actuating..- irame includingl a -substantially horizontal: first. arm disposed to be operatedsbyazkeyy a second: arm engaging said hammer: for. actuating yther. same, one of said arms having an abutment there-' on, and a third arm hinged-to the other; offsa'id's' first two mentioned arms and normallyengagingi said abutment, and-:m'eansvfor:disengagirigssaid: third arm from-fsa-id. abutment. to collapse said; frame at a predetermined-pointini the=travel ot said hammer,- thereby to :permit isaidzhanmi'ermto i all back from string-striking. position prior. to. release of its associated-keys l0. Anlaction for a pianozincludingia plurality). of keys comprising aapivoted strikingahammerp 75' same;saidfirst.arm

and: a thirds-arm hinged to said.- second-arm ..and 9 normally engaging said abutment, andmeansfor 1 from saidabutment totcollapse said frame 1 at a predetermined point; hammer, thereby to permit: back from stringestrikinggi ins-the travel: of said a single pivoted'rigidasingle pivoted rigid three-part hinged actuatingi; frame including a substantially horizontal. first w arm: disposed .to-beoperatedby: a key, ,a second: arm-1--engaging.said2 .hammer having an abutment. thereon;

disengaging said third: arm

saidr hammer .to. fall position :DITiOI' ztorelease of=its associatedkey.

11. .An action for. a piano including a'pluralityi; hammen:

a pivotedestriking hinged actuating frame eluding a substantially horizontal first arm dis-1; posed tozbe operatedby a key, 'a'second arm engaging said'hammera ofszkeys; comprising,

engaging said abutmentandmeans forrdisengaging' said third armirom said abutment to 1col-'-..

lapsesaid frame at a predetermined.pointxin the '1 mmer, thereby to permit 2 said: hammer. to fall backirom string-striking position'i travel of said ha prior. to-release of its associated key;

12; Aniaction for a piano including a. plurality oiikeys comprising; a

saidxhammer .lzaeingirTee.to. move independently;

ofii'said mechanism, and: a stop 'inithe pathzof." :2, movementtof said'fiy-iack for actuating the gamer a predetermined;

" key:

13'. Anaction of= ke'yscomprising, a pivoted striking hammer; a :single pivoted normally rigid collapsible aotu=-'- ating 'm'echanism= disposed to be operated by a key and engagin'gsaid hammer for actuating the same, said hammer being free to move independ ently of-said mechanism, means said mechanism at a predeterminedpoint in the travel of said hammer to permit said hammer to fall-.back f'rom string-striking position prior to release of its associated key, and means for limiting the extent of collapse :of said 'mech-- anism to support said hammer near string-strikiin'g-position.

14; Anaction for a piano including-a-pluralityofake'ys comprising, a pivoted striking hammer,- -=a single pivoted rigid hinged actuating frame ineluding a substantially horizontak'first arm= dis-' posed to be operated by-a key;-a second arm en-' gaging said hamm'erforactuating the'same, one

oi said arms having an abutment thereon, and a third arm hinged: to the-other of'said first -tw0-= mentionedarms andnormally engaging said abutment, and means for disengaging: said third arm from said abutment to *collapse said 'frameat a predetermined pointin the travel of said ham mer, thereby topermit said hammer to fallbackfrom string-striking position 'prio'r I to release of. its iassociated key, and a stop'on one of said first= and "second:'armsforengaging the other'upon' collapse of said frame-to limit the extent of-collapsethereof thereby to-support said hammen. near :string striking; position; .l

15. action ior. a piano .includinga plurality; ofwkeys' 'comprisingr;.a pivoted. strikingehammergi "for. aotuatingithew for actuating the -same,r.said" second-arm having an abutment/thereon, and a third arm hinged to said first. arm and. normally;

pivoted striking hammer; a single pivotednormally rigidcollapsible actuating .v mechanism including 1 a fly-"j acktasi an? element; thereoiian-ddisposed to be operated by a'keylandx engaging. said hammer: for actuating the same, 1.

for a piano including a plurality for collapsing a mIlglE pivoted rigid hinged actuating frame inin the travel of said hammer to permit said hameluding a substantially horizontal first arm dismer to fall back from string-striking position posed to be operated by a key, a second arm prior to release of its associated key, and adjustengaging said hammer for actuating the same, able means for limiting the extent of collapse of one of said arms having an abutment thereon, 5 said mechanism to support said hammer near string-striking position, both of said adjustable two mentioned arms and normally engaging said means being accessible for adjustment above the abutment, an adjustable stop in the path of piano keys. movement of said third arm for disengaging the CHARLES FREDERICK STEIN.

REFERENCES CITED The following references are of record in the striking position prior to release of its associated file of this patent;

and second arms for engaging the other upon UNITED STATES PATENTS collapse of said frame to limit the extent of col- Number N t lapse thereof, thereby to support said hammer 719,120 n t Jan 7 903 near string-striking Position 2,0s1,154 Heitzmann May 17, 1936 16. An action for a piano including a plurality 2,116117 Homm May 3, 1933 of keys comprising, a pivoted striking hammer, 2,266690 Martin 9 a single pivoted normally rigid collapsible actuat- 20 2 329 09 5 m Sept 7 1943 ing mechanism disposed to be operated by a key and engaging said hammer for actuating the FOREIGN PATENTS same, adjustable means for collapsing said Number Country Date mechanism at a predetermined adjustable point a 20,340 Great Britain July 4, 1907

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